1. Field of the Invention
The present invention relates to a method for processing nodes in 3-dimensional (3D) scene and an apparatus thereof, and more particularly, to a method for processing nodes representing 3D mesh information among nodes in a 3D scene and an apparatus thereof.
2. Description of the Related Art
Though 3D graphics is widely used recently, the scope of application is limited due to the huge volume of its information. That is, to represent 3D mesh information, geometry information of each point, connectivity information between each point, and information on properties such as color tones, normals, and texture coordinates. Generally, due to the huge volume of this information, it has been needed to encode this information, and for this, a 3D mesh coding (3DMC) apparatus, which has been adopted as a standard of International Organization for Standardization/International Electrotechnical Commission (ISO/IEC) by Moving Picture Expert Group-Synthetic and Natural Hybrid Coding (MPEG-4-SNHC) part, encodes and decodes 3D mesh information, which can be represented by IndexedFaceSet, to provide enhanced efficiency of transmission and encoding.
Meanwhile, the MPEG-4 system part is standardizing a Binary Format for Scene (BIFS) as a scene description language for specifying the expression method and properties of an object. The scene description language includes a Virtual Reality Modeling Language (VRML) and Web3D in addition to the BIFS.
In the BIFS of the MPEG-4 system and VRML, a 3D scene can be formed and the 3D scene contains an IndexedFaceSet node to represent 3D mesh information.
However, in the BIFS, 3D scene information having the huge volume of IndexedFaceSet information is simply compressed into binary codes, and in the VRML, is stored and transmitted after represented in the form of ASCII characters.
Therefore, in the MPEG-4 system, when 3D scene information including an IndexedFaceSet node having the huge volume of 3D mesh information is transmitted to a terminal through a BIFS stream, due to the huge volume of the IndexedFaceSet node information, transmission delays or decoding delays can occur, and therefore can cause a problem in which 3D scene information cannot be restored in a predetermined time.
In addition, even though this information is encoded, the volume of a large volume 3D mesh can be greater than that of other information contained in the 3D scene, and if encoded 3D mesh information is transmitted together with 3D scene description information in one stream, the transmission of the entire 3D scene can be affected.